Research And Development Of Alkylation Production Process

With the increasing emphasis on environmental protection by the international community,automobile emission regulations in various countries have become more stringent.In addition,various industries in China are booming.Haze and haze has frequently appeared,and the upgrading of gasoline has become an integral part of ecological civilization construction.The environmental protection regulations promulgated by the government a few days ago are gradually getting in line with international standards.Under this situation,alkylated oil as a clean gasoline blending component will surely go further in the future of oil upgrading.In this paper,the sulfuric acid alkylation process was studied in detail,so that the double greening of process and product was achieved by improving the production process and the reactor.Aaccording to the output of alkylated oil of 250,000 tons/year,the production process was simulated which raw material was from C₄ after MTBE of a refinery company in Shandong and adding a small amount of hydrocracking liquefied gas,and a mathematical model was established for the entire process using Aspen Plus process simulation software.A catalytic distillation tower was used in the raw material pretreatment process.Based on the characteristics of the process and the nature of the material,suitable unit modules and physical properties were selected.The mixture of hydrocarbons was PENG-ROB,and the mixture of acid and hydrocarbon was ELECNRTL.Then the whole process flow is simulated.Through continuous debugging,the results showed that the process converged,and the yield of alkylated oil reached 98%,which basically in line with product requirements.Optimization analysis was carried out for each section of the process,focusing on the sensitivity analysis of the catalytic distillation tower and debutanizer tower.After pretreatment by the catalytic distillation tower,the raw materials were basically free from C₃ components,the mass fraction of C₂H₆O was reduced to 243ppb,and the mass fraction of C₄H₆ was 13ppb;After optimization,the optimum operating parameters of debutanizer tower were 15 plates,the 7th plate was liquid feed,the reflux ratio was 1.3,and the top recovery rate was 0.28.Based on the optimization of all sections,the whole process simulation was conducted again.The inlet and outlet temperatures of the alkylation reactor was stabilized at about 0.4?,which is 7⁸?lower than the traditional process.The final alkylated oil yield was 3×10⁴ kg/hr,of which trimethylpentane accounted for 88.4%and dimethylhexane accounted for 5.1%.The octane number?RON?was 96.7 and the motor octane number?MON?was 93.3,which is about two units higher than the conventional process.Aiming at the emphasis of the alkylation reactor--enhancing acid-hydrocarbon mixing process,the acid hydrocarbon injection distributor was designed and improved.The flow field simulation of its internal mixing condition was performed using Fluent software,and internal distribution was investigated through the distribution of the flow fields.The simulation results showed that the distributor was designed reasonably.It could achieve adequate mixing of isobutane and sulfuric acid.When the sulfuric acid feed was 200m³/hr,the ratio of acid to hydrocarbon in the distributor reached 1.05:1,which is the best alkylation feed state and reached the design requirements.